Balloons have been used as a source of entertainment for a number of years. Children as well as adults have been attracted to the presence of balloons.
Furthermore, balloons have been used as a source of locomotion and to provide the users of the balloons with an advantage of extending the viewing range of the users of the balloons due to the height that the balloons may be raised to. Balloons typically are lightweight and consequently can be assembled and disassembled and moved from one site to another fairly quickly and easily as result of the lightweight nature of the balloons. The balloons are generally formed from a flexible yet strong material and the balloon material may be expandable in response to fluid pressure applied generally to the interior surface of the balloon. In most cases, pressurized air is used to expand the balloon.
State-mandated testing is an important part of today's teaching curriculum in both public and private schools. A significant part of the teaching day is directed to helping the students master the state objectives at various grade levels in order to perform adequately for this state-mandated testing. A difficult topic to teach today's students involves how the Earth was formed and how the Earth is changing over time. One factor which contributes to making this a difficult topic is the lack of models or real-life examples of this change.